The stability and robustness of the control system for a dual hybrid system's permanent magnet synchronous motor are analysed. Various control techniques, such as current vector control, flux weakening control, PI current control, and SVPWM control, are examined. The motor operates in different modes including initialization mode, normal mode, fault mode, active discharge mode, and power down mode. To ensure occupant safety and prevent damage to vehicle components when facing obstacles like high resistance or steep uphill slopes, motor stall control is implemented. Active short control is defined to avoid feedback of motor current to the battery through the continuous current diode of the IGBT and minimize excessive braking torque generated by the back electromotive force after closing the three-phase bridge arm at high speeds. Finally, successful validation of the motor control design is achieved through real vehicle testing.
With the development of science and technology and the worsening of human environment, the deepening of human environmental awareness makes photovoltaic power generation technology, as one of the main green energy sources, more and more widely used. At the same time, the surface of photovoltaic panels is polluted by sand and dust during use, which affects the efficiency of photovoltaic power generation. Therefore, the cleaning of photovoltaic panels is very important. However, the existing cleaning equipment, such as high-pressure water gun and scraper, has low working efficiency and unsatisfactory cleaning effect; In this context, we designed and developed a portable PV power panel cleaner with compact structure, light weight, durability and easy operation according to the needs of relevant enterprises. Field experiments on design samples show that the cleaner meets the design requirements and meets the market needs.
Proton exchange membrane fuel cell (PEMFC) vehicles are considered the ultimate form of automotive development due to their zero emissions and high energy conversion efficiency. The hydrogen supply system is crucial to the operation of PEMFC vehicles; efficient hydrogen supply improves hydrogen utilization, increases the hydrogen equivalence ratio, and reduces water blockage on the anode side. Ejectors, with their simple structure, small size, and no parasitic power, have attracted widespread attention. This paper establishes an automatic simulation platform for coaxial nozzle ejectors to study the impact of different operating conditions on ejector performance, and compares the working performance of coaxial nozzle ejectors with traditional single-nozzle ejectors under different loads.
With the acceleration of the pace of modern urbanites, the requirements for dishwasher is more towards the functional direction. People hope that the dishwasher can realize the function of automatic and fast cleaning of the tableware, and the intelligent dishwasher arises at the historic moment. This design is an intelligent dishwasher based on the 51 single chip computer. There are three washing modes, etc. the whole process is automatically completed by the intelligent dishwasher, and the user only needs to set the mode. If the water level is too high, it will be alerted to remind the user, and the working status information of the intelligent dishwasher can be displayed. The system has low cost, simple structure, stable work, the use of less devices, to realize the intelligent dishwasher intelligent control, can meet the different needs of users, has a certain practical value.
This article conducts a detailed and in-depth analysis of the work roadmap of the hydrogen fuel cell vehicle industry in Jinhua, combined with the development direction and trend of hydrogen fuel cell vehicle technology. Though extensive investigation and research, and based on the guidance of Jinhua province to accelerate the cultivation of hydrogen energy industry development, it analyzes the research background, formulation basis, standard analysis and implementation prospects from four aspects. We provide theoretical support for the government to formulate relevant industrial policies, guide the healthy and rapid development of the hydrogen fuel cell vehicle industry in Jinhua.
With the deepening of energy structure transformation, new energy sources such as photovoltaics and wind power are important means to achieve carbon neutrality in the future. In order to solve the instability problem of their use, research on electrochemical energy storage systems has become a key aspect. In addition, lithium-ion batteries play an important role in electronic devices, but their lower theoretical specific capacity makes it difficult to meet the needs of large electronic devices. Lithium-sulfur batteries have a theoretical specific energy density (2600 Wh•kg-1) and theoretical specific capacity (1675 mAh•g-1) several times higher than lithium-ion batteries, and they have abundant elemental sulfur reserves and low prices. Therefore, lithium-sulfur batteries are very promising energy storage devices. The positive electrode material has an important impact on the performance of lithium-sulfur batteries and has been widely studied. This article investigates the effect of different sulfur cathode thicknesses on the performance of lithium-sulfur batteries.
This project proposes to use a combination of machine learning and time series analysis to provide in-depth analysis and forecasting of electricity consumption in a city in North Africa. The dataset used in this study contains a range of information including date, temperature, humidity, wind speed, total flow, and electricity consumption. The project proposes to reveal patterns and patterns of electricity consumption behavior through data preprocessing, normalization, and seasonal decomposition. The project proposes to use two models: Seasonal Autoregressive Integrated Sliding Average (SARIMA) and Random Forest based on feature engineering. The SARIMA method is used to analyze the seasonality and trend of the time series data, and the Random Forest method is used to study the nonlinear relationship between electricity consumption and environmental factors. On this basis, we add more information such as rolling rolling standard deviation, minimum large value, and time-delayed features to the random forest. This method greatly improves the prediction accuracy of power consumption. The experimental results show that compared with the single SARIMA model, the random forest model using j combined with the feature engineering method can better predict the load changes of the power system. The results show that the Random Forest model can capture the complexity of power consumption more effectively, especially after adding detailed feature items. At the same time, the good interpretability and flexibility of Random Forest makes the model able to better understand and predict the urban power demand, which can effectively help the power grid enterprises to realize the optimal allocation of resources and reduce energy consumption.
Advances in IoT technology have made physical devices smarter and more accessible, allowing these devices to be used in a wide range of complex and necessary operations such as agriculture, food supply, smart cities, and health monitoring, while the core concept of the smart home is to use carefully designed management features and integrate the latest information and communication technologies and energy technologies to provide residents with a convenient, safe, entertaining, and comfortable living environment . This study reviews the integration of Internet of Things (IoT) technologies with smart homes, synthesizing the key findings from 20 articles from Web of Science, 2 articles from Google Scholar, and 4 articles from IEEE related literature. It is shown that the integration of IoT technologies with smart furniture systems has significant results in improving connectivity, automation and efficiency in residential and office environments. Although there are some challenges, they can be addressed by taking appropriate measures and have already contributed to the widespread adoption and development of smart furniture technologies. The application of IoT in smart furniture heralds future trends and potential opportunities for smart lifestyles.
Photomultiplier tube (PMT) is a commonly used optical detection device in life science instruments, and its performance is crucial to the accuracy and sensitivity of the instrument. This article provides a detailed analysis of the accuracy of PMT bias circuits and proposes some improvement methods to enhance the performance of PMT. By introducing temperature compensation and stability improvement techniques, we have successfully suppressed the adverse effects of temperature and parameter drift on the PMT bias circuit, thereby improving the accuracy and stability of voltage division. The experimental results indicate that these improved methods have made significant progress in the application of photomultiplier tubes in life science instruments, providing effective solutions for precise measurement and reliability of the instruments. These improvement methods provide useful guidance and reference for further improving PMT performance and developing more advanced life science instruments.
Fault prediction and diagnosis technology in the power system is an important application field of intelligent algorithms. Intelligent algorithms play a key role in fault prediction and diagnosis technology in the power system, aiming to improve the accuracy and efficiency of fault detection. This article reviews the current development status of intelligent algorithms in fault prediction and diagnosis technology in the power system, summarizes several problems and corresponding countermeasures of several commonly used intelligent algorithms in fault diagnosis applications. Finally, the development trend of intelligent algorithms is discussed: by focusing on data quality and integrating multi-source data, optimizing the selection and parameter tuning of algorithms and models, as well as combining multiple algorithms and models, the effectiveness and accuracy of fault prediction and diagnosis in the power system can be improved, enhancing the stability and reliability of the power system.
In view of the existing variable flux permanent magnet synchronous motor with limited range of magnetization and no automatic control of magnetization accuracy, an intelligent variable flux permanent magnet synchronous motor with auto-rotating permanent magnets and rotor built-in drive controller (IVFPMSM) is proposed. This paper analyzes the internal structure design and operation principle of this intelligent variable flux permanent magnet synchronous motor (IVFPMSM), and numerically analyzes the electromagnetic characteristics such as induced electric potential, winding magnetic chain, air gap flux density and weak magnetic characteristics when the permanent magnets (PMs) rotate at 0°, 30°, 45° and 90°, respectively. The results show that the PM can be rotated at any angle under the composite drive, which greatly widens the range of motor magnetization. The validity of the theory and design is verified by making a prototype and building a test platform.
Advanced control strategy has important application value in stability analysis and optimization of energy and power system. The main purpose of this study is to explore the application of advanced control strategy in the stability analysis and optimization of energy power system, and verify its effectiveness and superiority through simulation experiments. Specifically, this paper deeply analyzes the stability of energy power system and its influencing factors; The principle of advanced control strategy and its application method in energy and power system are studied. The optimization method of system stability based on advanced control strategy is proposed and verified by simulation experiments. The experimental results show that compared with the traditional control methods, the advanced control strategy in this paper can better adapt to the complex and changeable system operating environment and diversified energy access requirements, and significantly improve the stability and security of the system. This study is of great significance to promote the in-depth development of the stability research of energy power system and ensure the reliability and safety of power supply. At the same time, it also provides new ideas and directions for future research.
With the development of automatic control technology, machine control has gradually replaced the complex and cumbersome manual control mode. Given the current situation in the aquaculture industry where high-temperature weather leads to algae overgrowth, damaging lake ecology, depleting oxygen in the water, and causing a large number of aquatic organisms to die, there is a need for the design of a mechanical ship for algae treatment. The device is designed with an underwater variable diameter telescopic rotary blade combined with ultrasonic vibration, a screw slide table structure, a new crank rocker structure, and a variety of sensors. The device also incorporates OPENCV's visual recognition system to achieve automatic harvesting of algae. This integration significantly enhances the efficiency of algae removal.
Agilent GC7890A gas chromatograph is an important analytical instrument commonly used in the laboratory, with high precision, high sensitivity and good stability. However, with the growth of use time, the instrument may encounter some common faults, such as the FID detector baseline abnormality, the occurrence of irregular ghost peak, and the large baseline noise. These faults will not only affect the normal use of the instrument, but also may cause adverse effects on the experimental results. Therefore, the analysis of the common faults of Agilent GC7890A gas chromatograph and the corresponding treatment methods are of great significance to ensure the accuracy of the experimental results and the normal operation of the instrument. This paper first provides an overview of the basic information, functional characteristics of the Agilent GC7890A GC, and the range of applications in the laboratory. Then, the installation and maintenance precautions of the instrument are introduced in detail, including the requirements of the installation environment, installation steps, daily maintenance and regular maintenance. Finally, this paper analyzes the common faults of FID detector, including baseline error, no response, random ghost peak and high baseline noise, and proposes the corresponding treatment methods and preventive measures.
Wafer-level Fan-out packaging (FOWLP) with multi-layer redistribution layers (RDL) emerges as a pivotal technology in 3D integration. Polyimide (PI) as an insulation layer in the construction of RDL is essential for FOWLP. The adhesion of PI has become a focal point of multi-layer RDL. This study focuses on solving the adhesion technologies for PI photoresist lithography to achieve four layer RDL. The adhesion of PI to both the complex substrate and varying RDL layouts is investigated as a significant determinant of package reliability, characterized predominantly by surface free energy (SFE). It reveals that improving the substrate morphology by flattening can significantly enhance the PI adhesion, thereby addressing fluctuations caused by temporary bonding defects. Techniques such as CF4 dry etching and optimization of the temporary bonding process were found effective in mitigating substrate imperfections. Furthermore, various surface treatments applied to the RDL layers were investigated to boost the interface adhesion between the RDL and PI. Notably, after subjecting the plated copper to a 180W, 3-minute Argon plasma atmosphere, we observed an increase in roughness to 12 nm and an elevation in SFE to 80.82 mN/m, markedly improving copper surface adhesion. Additionally, employing Plasma-Enhanced Chemical Vapor Deposition (PECVD) to deposit SiO2 on the surface of the RDL layer substantially increased the SFE to 83.1±0.7 mN/m, demonstrating the most significant enhancement in PI adhesion. These advancements propose promising pathways to improve the structural integrity and reliability of FOWLP.
With the sustainable development of our country and the rapid economic development, the ground-source heat pump system is a renewable and clean energy system, which conforms to the concept of sustainable development of our country. This paper mainly discusses the working principle, classification, characteristics and advantages of ground-source heat pump technology.
With the rapid development of China's social economy, people's living conditions are also constantly improving, in China's current urban development, basically all buildings are equipped with elevators to facilitate people's daily travel. However, some problems will inevitably occur during the use of elevators, and elevators due to their characteristics, once there is a problem, there may be casualties. Therefore, in the current social development, more and more attention is paid to the safety performance of elevators, and the elevator must pass the performance test before use, and the safe elevator can be put into use. However, the performance testing of elevators also has certain influencing factors, and it is precisely these influencing factors that lead to the unstable detection of elevators, so in the current social development, it is necessary to strengthen the inspection and testing of elevators to ensure the safety and stability of elevators in use.
With the global climate change, the continuous consumption of non-renewable energy and the improvement of human requirements for environmental protection, the concept of carbon emission has gradually become popular. One of the main ways to reduce carbon emissions is to use clean energy, among which solar energy is a kind of renewable clean energy that can be widely used. Based on the basic principle of solar cells and through the classification of solar cell materials, this paper introduces the research status of solar cells prepared by the first generation semiconductor silicon and the third generation semiconductor InGaN/GaN, and summarizes the main optimization methods and principles of solar cell efficiency. Silicon nanowire solar cells are rich in raw materials and easy to be prepared. They are the most widely used solar cells at present, but their efficiency is low and needs to be improved. The main method is to optimize their nanowire structure and material surface properties. InGaN/GaN nanowire solar cells can improve their photoelectric conversion efficiency by adjusting the In component, which is also the direction of improving the efficiency of the third generation semiconductor solar cells. Finally, the future development direction is proposed, which can provide the direction and basis for the efficiency optimization of nanowire solar cells.
"Electricity for water" is an indirect measurement method of agricultural irrigation water. It establishes the quantitative relationship between irrigation electricity consumption and water withdrawal, and uses irrigation electricity consumption data to calculate irrigation water consumption indirectly. The conversion coefficient of electricity and water refers to the ratio of irrigation water to electricity consumption. Through the comprehensive analysis of 56 typical Wells and all irrigation Wells, it can be seen that the electric-water conversion coefficient of camellia Zhongji irrigation machine and electric well presents the following rules: (1) The electric-water conversion coefficient is larger in the high-yield (good water yield) area among different water levels.(2) Within the same water level or between adjacent water levels, when the difference between the water level is small, it is related to the old and new pumps. The newer the pump, the higher the use efficiency, the lower the power consumption, and the greater the water conversion coefficient.(3) Within the same water level or between adjacent water levels, the same depth of the irrigation well is related to the rated water output of the pump. The higher the rated water yield, the better the water yield and the greater the conversion coefficient of water yield. (4) When there is little difference in the amount of water within the same water level or between adjacent water levels, it is also related to the pump head. The smaller the pump head, the greater the power consumption, the greater the water conversion factor. In addition, it is also related to many factors such as line loss and well depth. Through the field measurement and data analysis, it is found that the conversion coefficient of electric water quantity is not only affected by a single factor, but also by the water quantity of each well, well depth, pump type, new and old pumps, pump head, line loss and other factors. Even in the same water level range, the electric-water conversion coefficient cannot show a certain rule on the plane.
For a vehicle, the brake pedal is a crucial component, allowing control over the vehicle's braking system by pressing the brake pedal, thereby achieving deceleration or bringing the vehicle to a stop. If the brake pedal has poor ergonomics, preventing it from being pressed to its extreme position, it can lead to reduced braking efficiency, increased braking distance, uneven braking, driver fatigue, and other issues. This directly affects the vehicle's road safety, increases the risk of accidents, and poses a threat to the safety of both the driver and passengers. The paper systematically analyzes the main parameters contributing to this issue, proposes rectification suggestions, addresses the problem of inadequate pedal ergonomics, and provides ideas and references for solving such problems.
